1. Field of the Invention
This invention relates generally to medical suction apparatus and more specifically to a suction apparatus which is adapted for the removal and processing of gasses, liquids and other debris from a surgical site.
2. Discussion of the Prior Art
Medical suction is commonly used for removing gasses and liquids from a surgical site to a remote location. The source of suction is positioned at this remote location and a suction tube typically extends between the source and the surgical site. In some cases, the material removed from the surgical site must be processed at the remote location in order to avoid contamination of the environment.
Suction requirements differ widely and vary, for example, with the size of the operative site and the nature of the material being removed. The availability and proximity of suction sources must also be considered along with their respective specifications for static suction, volume of movement, and filtration. The proximity of the suction source to the surgical site, and hence the length and size of the tubing extending therebetween, must also be considered.
Two types of suction sources are presently available in most operating rooms. The first is a smoke evacuator which is a portable, stand-alone device which removes surgical smoke from the operative site and filters that smoke prior to releasing clean air to the operating room. A surgical smoke evacuator typical of this type apparatus is disclosed and claimed by applicant in U.S. patent application Ser. No. 07/960,934, filed on Oct. 14, 1992 and entitled Surgical Smoke Evacuator.
This apparatus is used for processing surgical smoke which commonly results from laser and electrosurgical procedures. This smoke interferes with visualization of the operative site and may also be contaminated. Accordingly, it is desirable that the smoke be removed from proximity with the patient, the surgeon and the operative staff.
The smoke evacuators are typically provided with adjustments or settings which control the velocity of the suction. Static suction in a range of 70 to 100 inches of water are common. This suction is typically delivered through tubing having an inside diameter of a 7/8 inch. This large dimension presents no problem considering the size of the operative site commonly associated with this type of surgery.
Another type of suction source is even more commonly available in operating rooms. This source is typically referred to as "wall vacuum" and is usually accessed through 1/4 inch tubing. Wall vacuum generates 200 or more inches of water suction, but at relatively low flow rates of only 1-2 cubic feet per minute.
In addressing suction requirements in an operating room, one must then consider the nature of the material to be removed from the surgical site. Fluid waste such as blood or irrigation fluids are commonly removed using the wall suction. The 1/4 inch tubing draws fluid from the surgical site and through a fluid trap or canister which is positioned along the tubing between the suction source and the surgical site. This system is considered adequate for most surgical waste in a fluid, low viscous state.
The relatively low flow rates associated with wall suction have made it totally ineffective in removing waste containing any debris. Such waste is commonly associated with orthopedic revisions of hip and knee joints. In these cases, the waste typically contains a significant amount of blood clot, fine bone debris, adhesive and other solids. Any attempt to aspirate this waste using the wall vacuum causes the suction tubing to become clogged with a thick mass of debris suspended in blood and irrigation fluid. Blood adds significantly to the complexity of this waste slurry. Blood which is exposed to air and left in a low velocity or stagnant state, tends to clot. This of course, can increase the viscosity of the waste slurry over time.
Although smoke evacuators have not been intended to address either liquid or solid waste, various attempts have been made to adapt these instruments for this purpose. Smoke evacuators commonly include large tubes having a diameter such as 7/8 to one inch. A hand piece such as that disclosed and claimed by applicant in U.S. patent application Ser. No. 7/888,974 filed May 26, 1992 is commonly provided at the operative end of the long tube. Tubing of this size is not at all suitable for use in orthopedic revisions due to the small size of the surgical site. Also, the large tubing associated with smoke evacuators generates a relatively low velocity. Consequently, the large mass associated with the complex slurry mentioned above will not move up the tube. The small tubing sizes typically associated with wall vacuum tend to fill with the slurry which then becomes too viscous to move. The low volume of air flow commonly associated with the smaller tubing also contributes to this adverse condition.
Since the available suction sources in the operating room have all been deficient in removing blood clots and other solid debris, the surgeon and his assistants have been required to alter their surgical techniques where this type of waste develops. In many cases, the solid debris has been manually removed from the liquid which has then been addressed with sponges and other techniques for removing liquid waste.